Preheat the oven to 180°C (350°F).
Line a cupcake tin with paper or silicon liners.
Mix all the ingredients except the vinegar, to give a stiff batter. Add the vinegar and mix well. The mixture should drop easily from the spoon so if necessary add a little more juice/water/non-dairy milk to achieve the right consistency.
Spoon the mixture into the cupcake liners so they are around 2/3 full.
Bake for 15-20 minutes at 180°C (350°F) until risen, golden, and a toothpick inserted into the centre of a cake comes out clean.
Cool on wire racks before serving.